I have a rear disk brake conversion kit for sale. 91 & Newer GM C/K 1/2 ton trucks. This kit is new in the box and never installed on a vehicle. (I installed another brand of rear disk conversion kit on my vehicle. The quality of this kit was never an issue. This particular kit works better on C trucks than K trucks although it was designed for both.) I believe the disk rotors used are 94-96 Chevrolet Impala rear disk rotors. They are 295mm in diameter and 20mm thick. Total height of the rotor is 60mm. Braided stainless brake lines are included in the kit and '88-up Corvette loaded rear disk brake calipers are used in this kit along with the caliper brackets.
This kit is no longer available. Dropping the price to $425. I paid over twice that for this kit and we'll see how it goes.